Why does the engine emission warning light come on?
1 Answers
During vehicle operation, the engine emission warning light may illuminate. Common causes for this phenomenon include: 1. Spark plugs: Due to prolonged use without replacement, excessive gap, carbon buildup, or internal damage. 2. Cylinder: A damaged ignition coil in one of the cylinders, causing that cylinder to malfunction. 3. Fuel pump: Internal short circuit in the fuel pump, preventing low-pressure fuel from reaching the required supply pressure, leading to engine shaking or stalling. 4. Intake system: Air leaks in the engine intake system, causing engine shaking. 5. Piston carbon buildup: Excessive carbon deposits on the throttle valve, valves, or piston top in cold engine conditions. 6. Valve seat: In one of the engine cylinders, poor valve seat sealing or carbon buildup jamming the piston ring, resulting in no cylinder pressure and causing engine shaking.